(a) Field of the Invention
The present invention relates to a limited slip differential and, more particularly, to a limited slip differential that can generate higher differential torque.
(b) Description of the Related Art
Generally, a limited slip differential performs an additional function over that of a standard differential; that is, it provides more driving force to the wheel with traction when one wheel begins to spin.
A limited slip differential can be classified into shaft-housing types and shaft-shaft types. The former is designed such that a differential case and a drive cam are integrally rotated, and the latter is designed such that a pinion shaft of a planetary gear unit and a drive cam are integrally rotated. Accordingly, the former is generally used in vehicles that require relatively low-torque while the latter is generally used in vehicles that require relatively high torque.
However, in recent years, as vehicles are used for multiple purposes, a limited slip differential with enhanced in performance is desired.
Accordingly, there is a need for limited slip differentials that can enhance limited differential torque so that the same can be effectively used for various types of vehicles such as regular automobiles, sports cars, and sports utility vehicles.
To meet the above need, the present invention provides a limited slip differential comprising a differential case having a central axis, the differential case being connected to an input shaft of an engine, a drive body coaxially disposed within the differential case, a planetary gear unit disposed around the drive body, a cam assembly for performing a differential action depending on a speed difference generated by planetary gear unit, and a multi-plate clutch assembly having outer plates connected to the cam assembly and inner plates connected to the drive body. The cam assembly comprises a drive cam for moving in a radial direction with respect to the central axis by a speed difference between drive wheels, and a piston cam is urged toward the multi-plate clutch assembly when the drive cam is displaced in the radial direction to engage the inner and outer plates with each other. The outer plates are connected to the drive cam. The outer plates are connected to the drive cam by a fixing member fixed on the differential case.
Preferably, the drive cam is designed to integrally rotate with a carrier connected by pinion shafts of the planetary gear unit.
Preferably, each of the outer and inner plates has an S-shaped section SO that the multi-plate clutch can be returned to an initial position when an urging force of the cam assembly is released.